The question can we hear aliens has an other side to it. That side is do alien hear our radio signals. This question has been asked and little bit answered also. It has been calculated how far out the radio signals go out from Earth in every direction. As the technology goes it does not look good for radio signal from Earth. Given the bandwidth that radio signal has to have to use in order to carry signals, as picture and audio to be detected.
In terms or radius on where our radio signals can be detected. I would not be surprised that common radio signals are not detected outside our own moon. The strongest one might be detected on Mars or even Jupiter. But beyond that they are not going to be detected in my option. So if aliens detect our radio signals, they are going to get rather close to Earth to do so.
This is might also be the reason why we here on Earth are not detecting any signals from other civilization. The transmission used on those worlds, if they are there to start with are not strong enough to reach our solar system. Our only chance of detecting alien signals might be to look for narrow band signals that can travel an long distance in interstellar space. But for us to find alien radio signals. We have to go out there and look for them the hard way.
There most likely is an alien civilization close to our own solar system. But we are just unaware of it due to the fact that we are unable to detect its radio signals due to distance. If they are present to start with. As not all alien civilization might be using radio signals, or be on that technical level yet.